whats up with this

is there any reason why some recipes when they want u to simmer say bring to a boil first than to a simmer,and other recipes never say anything about boil first just say simmer ingr. ,is there reasons for this? any one have an idea why this is?

I would define simmer as just below boil. It does not require you to bring it to a boil first. However the quickest and easiest way to bring something to a simmer is to use high heat to bring it to a boil, and then back off on the heat. Without the visual clue of boiling it is hard to target a simmer.

There may be some items that benefit from a period at boil before simmering. Beans come to mind. Rice is almost always brought to a boil first, but I'm not sure that's a requirement.

On the other hand, when 'scalding' milk, you want to bring it up to a simmer, staying away from a boil. The temperature difference isn't big, but boiling milk boils over.

It would help to point to specific recipes. We could then discuss whether the author just omitted the boil step (assuming the cook would still do it), or whether you should stay away from a boil in that case. Recipes are not all refined to the same degree, or make the same assumptions about the cook's knowledge.

the recipe i was looking for was for sloppy joe.....one i think was on this site and they didnt boil first and another recipe for sloppy joe i have said boil and then bring. to simmer. Sloppy Joes (from Allrecipes.com)

Directions:1. Place ground beef in a large skillet over medium heat. Cook until evenly browned, stirring to crumble. I like to use a potato masher to even out the lumps. Add onion and celery, cover the pan, and cook until tender and transparent, about 5 minutes. Drain off any grease. 2. Stir the tomato soup (undiluted), ketchup, vinegar, brown sugar and Worcestershire sauce into the beef mixture. Season with salt and garlic powder. Heat to a simmer over low heat, and cook until thoroughly heated, stirring frequently to prevent it from burning on the bottom. 3. Spoon the hot beef mixture onto buns, which may be toasted first, and serve.

I think the author is worried about burning if the heat is too high. It looks like the sauce part is thick and sweet, and could easily burn. If you have good heat control (gas or induction), and are diligent with stirring you could get by with higher initial heat. Otherwise stick with lower heat.

The boil then simmer direction makes more sense with the sauce/stew/soup is initially quite soupy.